ok then. Mutation is a term refered to specifically as a change in the sequence of a DNA molecule. Of course RNA polymerase and the ribosome can make mistakes, but they are not called mutations. That's in cells at least. In riboviruses, for example, that have an RNA genome, a change in the sequence of that RNA is considered a mutation. Nothing about proteins can ever be a mutation.

I still don't understand something: if you're not a biologist, why are you teaching a biology course?

"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter

hi ,, I know it's an old topic an all , but I'm just amazed of the answers really !!and I wanna leave something to Myth - dear I think you just missed the first principle in Science , which is Ego and science can't never be on the same line !! - and when we lose the ability to ask why, we lose the ability to reach the ultimate secret of life which is our first goal as a biologist- bio teachers - professors- biofans .. so good luck !!God help me when I ask my questions to you people !bye

However, ego is not the issue here. Note that we've replied to countless people who've shown that they have tried to answer their own homework problems and yet we also have countless lazy students who want answers and would stoop to very low levels to get them. Perhaps in this case we've erred on the side of caution.

And the first principle of science is not about ego. Being humble can but doesn't make you a better or worse scientist.

Living one day at a time; Enjoying one moment at a time; Accepting hardships as the pathway to peace; ~Niebuhr

um I think that you're right about that .The first principle in science could be an issue , according to my genetic professor in my first year in college he said to us in our first class - you are studying biology you are the master of life- I believe that He made that statement from something , me I got my first principle from a paper I once did about hydrogen bomb and its ecological effects , when I realized the ego of some scientist driving them behind a fade glory !! .. that killed life in many shapes ! and for me that's what separate between good and bad scientists ,I'd love to know your first principle ???

Poor CH. Some of you guys sound like a bunch of first graders trying to make others feel bad for wanting to LEARN something instead of already knowing it.

Isn't that what this forum is for? Learning and sharing knowledge? Not for showing off and teaching?I'm sorry that I don't know the answer, CH, I was hoping to learn more by your question, as I am a student.

Who might just be ridiculed for not knowing the answer to something...?

I am a cell biologist, however not a specialist of mutations. Nevertheless my feeling is the following: There are 2 types of mutations. Mutations of germ cells (spermatozoïds and ovules) and mutations of somatic cells (the other ones). Mutations of germ cells are in the genetic program because they are here to create genetic diversity of the first cell, the zygote (for instance what is called the crossing over between sister chromatids). Mutations of somatic cells are related to the fact that systems replicating and repairing DNA are absolutely extraordinary but not 100 % perfect (A DNA polymerase can make an error every 100 millions bases replicated but there are 3 billions bases to replicate in a cell). The first cell of the embryo will divide in life around 45 times to create the 30 000 billions cells of a human body (1, 2, 4, 8, 16, 32, ...,30 000 billions cells). Each division means that DNA was replicated and repaired before the cell division. This "imperfect" mechanism implies the possibilities of somatic mutations.

Just because someone is a teacher doesn't mean they know everything. By the way Mith, I tried to add you to my foes. For some reason I couldn't. It said I can't add moderators or administrators to my foes. What exactly is a moderator or administrator, and why are you one? It doesn't seem like you have the right background...